In the robotic industry, parts are positively located with tooling for work thereon. The robotic-controlled tooling is normally mounted in a robot work cell or system. In many applications, the tooling is rotated around a centerline through the tooling, with a servomotor and gearbox to set specific desired locations or index points. The rotation may be accomplished in numerous ways, such as with well known rotary pistons. Often times, the tool rotation needs to be limited to less than 180xc2x0. However, there is a high cost for implementing the controls and power for limiting the rotational movement generated by the servomotor. Therefore, there is a need for a low cost system for rotating tooling between 0 and 180xc2x0 for robotic welding.
Accordingly, a primary objective of the present invention is the provision of a fluid powered rotary indexer for use in robotic-controlled processes.
Another objective of the present invention is the provision of a device for efficiently and economically rotating robotic tooling to selected angular degrees.
A further objective of the present invention is the provision of a plurality of assemblies which can be interconnected in series so as to perform sequential rotational steps for robotic tool work.
Another objective of the present invention is the provision of a rotary indexer which replaces the servomotor in robotic tooling operations.
Another objective of the present invention is the provision of a plurality of assemblies which are connected in parallel so as to provide increased torque for rotating robotic tooling.
These and other objectives will become apparent from the following description of the invention.
The present invention is directed towards an assembly for rotating tooling to a selected angular degree for robotic welding. The assembly includes a housing with a chamber therein, and a piston rotatably mounted in the housing. The piston includes two arcuate portions with different radii. A sealing ring extends around the piston so as to divide the chamber into two compartments. Fluid ports are provided in the housing to provide fluid communication to each of the compartments in the chamber. When fluid is introduced into one compartment, the piston is rotated, thereby expelling fluid from the other compartment. Sealing rings are provided between the piston and housing to provide a fluid seal for the compartments. The piston is rotationally supported in the chamber by a bearing. An adapter is connected to the piston and is adapted to support the tool for rotation with the piston.
Two or more assemblies may be interconnected in series or in parallel. When connected in series, each assembly can be sequentially activated so as to sequentially rotate the tooling to first and second desired positions for sequential robotic tooling steps. When the assemblies are connected in parallel, the pistons rotate in unison to provide increased torque for the tooling.